The present invention relates to a mechanical fastener closure tape tab laminate for use on disposable articles, generally a disposable absorbent diaper.
Closure tape tab laminates utilizing mechanical fasteners are known in the art with the mechanical fastener generally located on a tape tab backing. The mechanical fastener is attached generally by the use of adhesives. The opposite end of the tab is generally permanently attached to one face of the disposable article with the mechanical fastener extending out beyond a side edge of the absorbent article for use in forming a closure with a mating attachment provided on a opposite end of the disposable article. Generally when the diaper or the like is packaged prior to use, it is preferred that the tab be folded back into the main body of the diaper. Otherwise the tab will extend out beyond the edge of the diaper and create problems such as inadvertently attaching to substrates as well as making it difficult to fold the article into a form suitable for an easily packaged product. As such, it is preferred that the mechanical fastener xe2x80x9cfree endxe2x80x9d be folded back onto the opposite face of the diaper prior to use. The problem of an unattached tab extending out beyond the edge of the diaper is generally known as flagging. The conventional approach to solving this flagging problem has been to provide a pressure sensitive adhesive somewhere on the tape tab laminate which would allow the tape tab free end to releasably adhere to a suitable surface on the diaper. The end user would then grasp a fingerlift on the tab and break this adhesive bond and extend the tab for use. Such an adhesive antiflagging configuration is disclosed, for example, in European Patent No. 321,232, where the adhesive is adjacent the mechanical fastener on the tab. European Patent Application No. 894,448 discloses providing pressure sensitive adhesive on the tops of mechanical fastener hook heads for antiflagging. Japanese Patent Application No. 8-2365 provides adhesive on the extended portion of the tab, which adhesive then transfers to the diaper such that there is no exposed adhesive on the free end of the tab when in use. The use of an exposed adhesive for antiflagging is also taught in PCT Patent Application No. WO97/28774. Although effective, the use of an exposed pressure sensitive adhesive is undesirable in many instances with a mechanical fastening system. For example there are many exposed fibrous surfaces on absorbent articles with mechanical fasteners, which fibrous surfaces can cause fiber contamination of the adhesive. Also there is undesirable reaction on the part of some customers to the use of exposed adhesives in mechanical fastener systems of this type. For these reasons and others there has been considerable work on a non-adhesive solution to the flagging problem.
The use of a non-adhesive approach to the flagging problem is proposed, for example, in European Patent Application No. 818,188. This patent document proposes releasably welding the tab free end to an inner surface of a diaper. Although effective, this is problematic in that it requires an on-line welding during the diaper manufacturing process, which can slow diaper production. Japanese Patent Application No. 10-137008 and U.S. Pat. No. 5,926,926 disclose the use of a separate small patch of loop material, which can engage with the hooks. These loop patches are generally placed where the antiflagging adhesive would be placed. The small loop patches suggested in these patents are unlikely to be entirely effective in providing for a reliable connection. Also these loops add significant bulk to the tabs creating the possibility of hard bands in the packaged diapers and making it difficult to provide long yardage rolls of prelaminated mechanical fastener tape tabs. European Patent Application No. 832,631 proposes a complicated structure involving a splitable nonwoven material. This would have similar issues as the use of loop patches and be difficult to manufacture. European Patent Application No. 853,935 discloses a complicated laminated tab structure, which comprises a tape tab backing having two adhesive coated portions with an adhesive free region separating them and a separate carrier for the hook. The hook carrier has a separate adhesive attachment zone and is perforated in an adhesive free zone. The carrier perforation is separable which allows the tab to be maintained in a folded condition prior to use and broken or torn to allow the tab to be extended. Although effective in maintaining a tab in a folded condition, this construction does not allow for a conventional Y-bond to provide a secure attachment to both faces of the diaper side edge and requires two complicated zone adhesive coatings on the tape tab backing and the carrier.
Although there are many varied techniques taught in the art to maintain a fastening tab laminate in a folding condition around the edge of a diaper prior to use, there still remains the need for an effective way of providing such an arrangement for a mechanical fastener tape tab laminate which provides for a combination of ease of construction, a reliable and secure attachment that is easily releasable by the user and which does not rely on exposed pressure sensitive adhesives and preferably in a construction that allows the possibility of providing a secure Y-bond to the edge of the diaper.